The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
A Zorin - One of the best experts on this subject based on the ideXlab platform.
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magnetic measurements of superconducting insertion devices by Stretched Wire with direct current
Physics Procedia, 2016Co-Authors: N A Mezentsev, V M Tsukanov, A ZorinAbstract:Abstract The main characteristics of multipole insertion devices (ID) are the first and second field integrals along an orbit trajectory in an accelerator. Such integrals of permanent magnets or traditional electromagnets insertion devices can be obtained by means of longitudinal scanning by Hall probes. Measurements of the magnetic field by Hall probes in superconducting IDs have obvious difficulties because of limited space, temperature deviation along the path, etc. Measurements of the integrals by Hall probes, especially when the integrals has to be equal to zero, it is very difficult to make with a necessary accuracy. At Budker INP along with Hall probes the system of magnetic measurements on the basis of the tense Wire with a direct current is used. The method is based on similarity of interaction of a direct current in a Stretched Wire and an electron beam in an accelerator with magnetic field. The Stretched Wire with current is a good model to describe behavior of an electron beam when passing through a magnet. Especially the method is useful at measurement of superconducting IDs where it isn’t enough space for other probes. The method provides a dynamic control of the field integrals in different modes of a magnet operation (field ramp up or down), allows to measure the integrals quickly and rather precisely.
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Magnetic Measurements of Superconducting Insertion Devices by Stretched Wire with Direct Current
Physics Procedia, 2016Co-Authors: N A Mezentsev, V M Tsukanov, A ZorinAbstract:Abstract The main characteristics of multipole insertion devices (ID) are the first and second field integrals along an orbit trajectory in an accelerator. Such integrals of permanent magnets or traditional electromagnets insertion devices can be obtained by means of longitudinal scanning by Hall probes. Measurements of the magnetic field by Hall probes in superconducting IDs have obvious difficulties because of limited space, temperature deviation along the path, etc. Measurements of the integrals by Hall probes, especially when the integrals has to be equal to zero, it is very difficult to make with a necessary accuracy. At Budker INP along with Hall probes the system of magnetic measurements on the basis of the tense Wire with a direct current is used. The method is based on similarity of interaction of a direct current in a Stretched Wire and an electron beam in an accelerator with magnetic field. The Stretched Wire with current is a good model to describe behavior of an electron beam when passing through a magnet. Especially the method is useful at measurement of superconducting IDs where it isn’t enough space for other probes. The method provides a dynamic control of the field integrals in different modes of a magnet operation (field ramp up or down), allows to measure the integrals quickly and rather precisely.
G. Le Bec - One of the best experts on this subject based on the ideXlab platform.
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Single sided dipole-quadrupole magnet for the Extremely Brilliant Source storage ring at the European Synchrotron Radiation Facility
Phys.Rev.Accel.Beams, 2019Co-Authors: G. Le Bec, S. Liuzzo, F. Villar, P. Raimondi, J. ChavanneAbstract:Combined function magnets with dipole and quadrupole components were designed and built for the Extremely Brilliant Source. These magnets are low power consumption single sided off-axis quadrupoles. The field of the magnets was optimized for particles with a curved trajectory and within an elliptical good field region. A specific moving Stretched Wire magnetic measurement method was developed for measuring the magnetic length of the magnets, the radius of curvature of the poles and the field multipoles. The effect of the curvature of the magnets on the field multipoles was investigated.
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High gradient quadrupoles for low emittance storage rings
Phys.Rev.Accel.Beams, 2016Co-Authors: G. Le Bec, S. Liuzzo, P. Raimondi, J. Chavanne, C. Benabderrahmane, L. Farvacque, L. Goirand, F. VillarAbstract:High gradient quadrupoles are key components for the coming generation of storage ring based light sources. The typical specifications of these magnets are: almost 100 T/m gradient, half a meter long, and a vertical aperture for the extraction of the x-ray beam. This paper presents the preparation work done at the European Synchrotron Radiation Facility, from the design to the manufacture and measurements of a prototype. It demonstrates the feasibility of such magnets. Different aspects of magnet engineering are discussed, including the study of the main scale factors and the preliminary design, the pole shaping, the impact of mechanical errors, and the magnetic measurements of a prototype with a Stretched-Wire system.
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Stretched Wire measurement of multipole accelerator magnets
Physical Review Special Topics - Accelerators and Beams, 2012Co-Authors: G. Le Bec, Joel Chavanne, Ch. PenelAbstract:Theoretical aspects of Stretched Wire field integral measurements are investigated. A least square approach is used for the processing of the measured signal; it can be applied to any Wire trajectory and it allows numerical correction of the Wire position errors. Moreover, the signal from some multipoles can be compensated for in a way comparable to the ``bucked'' rotating coil method. This can be used for accurate measurements of field multipole errors. A Stretched Wire bench has been built at the European Synchrotron Radiation Facility. This bench has been used for measuring dipole, quadrupole, and sextupole magnets. The results obtained with various Wire trajectories are compared. It is demonstrated that an accuracy of a few ${10}^{\ensuremath{-}4}$ of the main multipole can be obtained.
Stephan Russenschuck - One of the best experts on this subject based on the ideXlab platform.
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Measuring the Field Quality in Accelerator Magnets with the Oscillating-Wire Method -- a Case Study for Solving Partial Differential Equations
arXiv: Accelerator Physics, 2020Co-Authors: Stephan RussenschuckAbstract:The single Stretched-Wire method is commonly used to measure the magnetic field strength and magnetic axis in an accelerator magnet. The integrated voltage at the connection terminals of the Wire is a measure for the flux linked with the surface traced out by the displaced Wire. The Stretched Wire can also be excited with an alternating current well below the resonance frequency. It is thus possible to measure multipole field errors by making use of the linear relationship between the Wire-oscillation amplitude, integrated field, and current amplitude. This technique is a good example for solving partial differential equations, or more precisely, boundary value problems in one and two dimensions. In particular, the field in the aperture of accelerator magnets is governed by the Laplace equation, which leads to a boundary-value problem that is solved by determining the coefficients in the series of eigenfunctions from measurements of the field components or Wire-oscillation amplitudes on the domain boundary. The oscillation of the taut string is an example of a one-dimensional, in-homogenous wave equation. The metrological characterization of the oscillating-Wire system yield the feedback on the uncertainties (and limitations) of the method, as only the linearized equations of the Wire motion and the integrated field harmonics of the magnet are considered.
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Development of a rotating-coil scanner for superconducting accelerator magnets
Journal of Sensors and Sensor Systems, 2020Co-Authors: Piotr Rogacki, Stephan Russenschuck, Lucio Fiscarelli, Kay HameyerAbstract:Abstract. The High-Luminosity upgrade project for the Large Hadron Collider (HL-LHC) at CERN (Conseil Européen pour la Recherche Nucléaire) will require new superconducting magnets for the insertion regions. Among these magnets, the new triplet quadrupoles, based on Nb3Sn technology, require magnetic-field measurements of a high precision in the field angle and multipole field errors. In this paper, we present a scanning system based on a rotating-coil magnetometer and its transport system, including the design of the mechanical structure and the induction coils based on printed-circuit-board (PCB) technology. The system and its components are cross-calibrated with other field transducers, such as Stretched-Wire systems, and their measurement precision is established in a measurement campaign of 2 m long reference quadrupoles.
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Boundary-Element Methods for Field Reconstruction in Accelerator Magnets
IEEE Transactions on Magnetics, 2020Co-Authors: Melvin Liebsch, Stephan Russenschuck, Stefan KurzAbstract:Magnetic fields in the aperture of particle accelerator magnets can be represented by boundary potentials, exploiting Kirchhoff's integral equation. Depending on the formulation, magnetic measurement data can be represented by the discrete approximations of Dirichlet or Neumann data at the domain boundary. The missing Cauchy data, which are related to the tangential-field components, can then be computed by the boundary-element method (BEM) in a numerical post-processing step. Evaluating the integral equation for field reconstruction inside the domain of interest will reduce measurement uncertainties and approximation errors due to the smoothing property of Green's kernel. Applications to the reconstruction of 2-D fields (integrated quantities from Stretched-Wire measurements) and 3-D fields (local quantities from measurements with moving induction-coil magnetometers) are presented.
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Boundary element method reconstruction of two-dimensional magnetic-field maps from measured boundary data in accelerator magnets
IET Science Measurement & Technology, 2019Co-Authors: Leonardo Biccioli, Luca Di Rienzo, Carlo Petrone, Stephan RussenschuckAbstract:Rotating-coil magnetometers are standard devices for measuring integrated magnetic fields of accelerator magnets. The coil intercepts the magnetic flux at a radius given by the dimensions of the measurement shaft that comprises a set of induction coils. For magnets of a rectangular aperture with a large aspect ratio (larger than 3:1) the cylindrical domain will cover only a portion of the magnet aperture. We, therefore, explore an alternative sampling technique using boundary data acquired from a displaced Stretched-Wire or from a translating fluxmeter. The method presented in this study concerns the reconstruction of the two-dimensional map of the integrated magnetic field distribution in the entire magnet aperture using the measured boundary data.
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Correcting for background fields and multipole field errors in the localization of the magnetic axis in quadrupole magnets
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2018Co-Authors: Pasquale Arpaia, Carlo Petrone, Domenico Caiazza, Stephan RussenschuckAbstract:Abstract The fiducial marker localization with respect to the magnetic axis of the magnet elements is a crucial step in the qualification of the magnets for particle accelerators. Background fields, such as the Earth’s magnetic field and fringe fields from electrical sources may degrade the accuracy of this axis localization. In this paper, we discuss Stretched-Wire measurements, in static and vibrating operation modes, for the correction of stray fields in the quadrupole axis localization to an accuracy of 0.3 μ m. Moreover, we present an analytical model to correct the magnetic axis position error due to higher-order multipole field errors in the magnet. This correction is particularly important for the static Stretched-Wire measurement because the Wire movement must be large enough to obtain a sufficient signal-to-noise ratio.
Li-song Yan - One of the best experts on this subject based on the ideXlab platform.
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Investigation of factors affecting vertical sag of Stretched Wire
Nuclear Science and Techniques, 2021Co-Authors: Jian-dong Yuan, Bin Zhang, Junhui Zhang, Wenjun Chen, Shaoming Wang, Guozhen Sun, Xundong Zhang, Li-song YanAbstract:To study vertical sag requirements and factors affecting the Stretched Wire alignment method, the vertical sag equation is first derived theoretically. Subsequently, the influencing factors (such as the hanging weight or tension, span length, temperature change, elastic deformation, and the Earth’s rotation) of the vertical sag are summarized, and their validity is verified through actual measurements. Finally, the essential factors affecting vertical sag, i.e., the specific strength and length, are discussed. It is believed that the vertical sag of a Stretched Wire is proportional to the square of the length and inversely proportional to the specific strength of the material.
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Investigation of Factors Affecting Vertical Sag of Stretched Wire.
arXiv: Instrumentation and Detectors, 2021Co-Authors: Jian-dong Yuan, Bin Zhang, Junhui Zhang, Wenjun Chen, Shaoming Wang, Guozhen Sun, Xundong Zhang, Li-song YanAbstract:To study vertical sag requirements and factors affecting the Stretched Wire alignment method, the vertical sag equation is first derived theoretically. Subsequently, the influencing factors,such as the hanging weight or tension, span length, temperature change, elastic deformation, and the Earths rotation, of the vertical sag are summarized, and their validity is verified through actual measurements. Finally, the essential factors affecting vertical sag, the specific strength and length, are discussed. It is believed that the vertical sag of a Stretched Wire is proportional to the square of the length and inversely proportional to the specific strength of the material.
Yuan Jiandong - One of the best experts on this subject based on the ideXlab platform.
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Investigation of Factors Affecting Vertical Sag of Stretched Wire
2021Co-Authors: Yuan Jiandong, Wu Junxia, Zhang Bin, He Yuan, Zhang Junhui, Chen Wenjun, Wang Shaoming, Sun Guozhen, Zhang Xundong, Yan LisongAbstract:To study vertical sag requirements and factors affecting the Stretched Wire alignment method, the vertical sag equation is first derived theoretically. Subsequently, the influencing factors,such as the hanging weight or tension, span length, temperature change, elastic deformation, and the Earths rotation, of the vertical sag are summarized, and their validity is verified through actual measurements. Finally, the essential factors affecting vertical sag, the specific strength and length, are discussed. It is believed that the vertical sag of a Stretched Wire is proportional to the square of the length and inversely proportional to the specific strength of the material.Comment: 19 pages, 6 figure
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summary of application of Stretched Wire technology in accelerator alignment and survey
High Power Laser and Particle Beams, 2020Co-Authors: Yuan JiandongAbstract:To study the application and development of Stretched Wire technology in accelerator alignment and survey, the principle of Stretched Wire technology is summarized firstly, then the development history of Stretched Wire alignment method in accelerator is reviewed, and the latest development trend of Stretched Wire alignment method is introduced. Finally, the advantages and disadvantages of various alignment methods and their suitable environments are discussed, and the development differences between domestic and foreign alignment methods are compared. The development direction of the Stretched Wire alignment method is pointed out, and the direction of the accelerator alignment and survey is given.